Illumination systems for illuminating a space with a variable color are generally known. Generally, such systems comprise a plurality of light sources, each light source emitting light with a specific color, the respective colors of the different light sources being mutually different. The overall light generated by the system as a whole is then a mixture of the light emitted by the several light sources. By changing the relative intensities of the different light sources, the color of the overall light mixture can be changed. It is noted that the light sources can be of different type, such as for instance TL lamp, halogen lamp, LED, etc. In the following, simply the word “lamp” will be used, but this is not intended to exclude LEDs.
By way of an example of a variable color illumination system, an illumination system in a theatre is mentioned. During a show, it may be desirable to change the color of the lighting. However, also in the case of homes, shops, restaurants, hotels, schools, hospitals, etc., it may be desirable to be able to change the color of the lighting. In the case of a theatre or the like, the colors are typically changed with a view to enhance dramatic effects, but in other situations it may be more desirable to have smooth and slow transitions.
The color of the lighting can be changed instantaneously by a lighting operator, who directly controls the individual lamps. In such case, the lighting operator may decide intuitively to change the lighting in response to changes in the scene, the ambient lighting, the reaction of the public, etc. The present invention, however, relates to a system with a programmable control device that controls the individual lamps in accordance with a predetermined program. A lighting designer conceives, in advance, a sequence of colors, and this sequence is programmed into a memory of the control device, either in the form of a program or, more likely, in the form of a table. Such table contains, for each moment in time, the required color point of the system or even the relative intensities of the different light sources. After inputting the separate color values, the designer can switch on the lamps with these color values to see whether the resulting color effect is to his liking. After having inputted a sequence of color values, the designer can run the lighting program to see whether the resulting color sequence is to his liking. In view of the fact that the designer has to program each color at each time step, programming dynamic color sequences is currently a difficult, time-consuming and tedious effort.
The present invention aims to provide a method and device with which the process of creating dynamic color sequences is made much more convenient and user-friendly.
As should be clear to a person skilled in the art, the color of light can be represented by coordinates of a color point in a color space. In such representation, changing a color corresponds to a displacement from one color point to another color point in the color space, or a displacement of the setting of the color point of the system. Further, a sequence of colors corresponds to a collection of color points in the color space, which collection will be indicated as a path. Dynamically changing the colors can then be indicated as “traveling” such path.
The examples mentioned above relate to situations where it is desired to illuminate a certain location with light having a certain color, and where it is desired to vary that color as a function of time. In such situation, at each moment in time there is basically one color point, and this color point is varied as a function of time. On the other hand, there are also situations where it is desired to illuminate a certain area with light having different colors, such that the color of the light in different locations of the area may be mutually different. In such situation, there is a distribution of color points over the area; in other words, the color points are varied as a function of location. The color distribution itself may be varied as a function of time, but in the present explanation it will be assumed that the color distribution is stationary, i.e. does not depend on time.
In such situations, an illumination system comprises an array of armatures, each armature comprising a plurality of light sources as mentioned above. Thus, each armature as a whole generates light (mixture) having a specific color point, which color point can be set by setting the relative intensities of the different light sources of that specific armature. The armatures can be controlled independently from each other, such that the color points of the different armatures may be mutually different.
The layout of the array of armatures will be chosen in relationship to the shape of the area to be illuminated. The array may be 1-dimensional (line-shaped array), so that the location of the individual armatures can be described by one place coordinate. The array may also be a 2-dimensional grid, so that the location of the individual armatures can be described by two place coordinates. The array may even be a 3-dimensional grid, so that the location of the individual armatures can be described by three place coordinates. The disposition of armatures in one dimension may be along straight lines, but such lines may also be curved. The mutual distance between neighboring armatures may always be the same, but this distance may vary over the area (and, to make things more complicated, may even vary as a function of time; but, as mentioned, the dependency of time will be ignored in the present explanation).
It should be clear that the actual distribution of color points of the light over the illuminated area depends on the layout of the array of armatures and the color points of the respective armatures, but also on the shape (spatial intensity distribution) of the respective light beams of the armatures. After all, most locations will receive light from more than one armature. It is very difficult and unpractical to describe the desired color distribution over the entire area. Therefore, in the following explanation, the phrase “spatial color distribution” will be used to indicate the distribution of the color points over the array of armatures. Thus, the “spatial color distribution” will be embodied by an array of color points.
For a designer who wishes to achieve a certain color effect, it will be necessary to calculate the individual color points, which is again a difficult, time-consuming and tedious effort, the more so as the number of armatures increases. Thus, the present invention aims to provide a method and device with which the process of creating spatial color distributions is made much more convenient and user-friendly.
In the case of a dynamic color sequence, the problem is basically to define a set of color points and to sequentially generate these color points; thus, the color points are generated as a function of the coordinate “time”. As mentioned, this can be indicated as defining a path in color space and traveling the path. In the case of a spatial color distribution, the problem is likewise to define a set of color points (again defining a path in color space), but now the color points are generated simultaneously by corresponding armatures; thus, the color points are generated as a function of the coordinate “place”. Thus, in general, the present invention aims to provide a method and device for calculating a set of color points in a convenient and user-friendly way.